3006178
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Isobutyryl/butyryl-carnitine (C4) Quantitative, Urine

C4 URINE
Example Reports
Abnormal
Normal

Ordering Recommendation

Aids in the differential diagnosis of short-chain acyl-CoA dehydrogenase (SCAD) and isobutyryl-CoA dehydrogenase (IBD) deficiencies. Order to follow up an abnormal newborn screen or plasma acylcarnitine profile with an isolated elevation of C4-carnitine. Use in conjunction with Acylcarnitine Quantitative Profile, Plasma (0040033), Organic Acids, Urine (0098389), and Acylglycines, Quantitative, Urine (0081170).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Random urine.

Specimen Preparation

Transfer 2.5 mL urine to an ARUP standard transport tube and freeze immediately. (Min: 1.0 mL)

Storage/Transport Temperature

Frozen. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Specimens that have been exposed to more than three freeze/thaw cycles.

Remarks

Clinical information is needed for appropriate interpretation. Additional required information includes age, gender, diet (e.g., TPN therapy), drug therapy, and family history. Biochemical Genetics Patient History Form is available on the ARUP Web site at https://www.aruplab.com/patienthistory or by contacting ARUP Client Services.

Stability

Ambient: Unacceptable; Refrigerated: 1 week; Frozen: 1 month

Methodology

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Performed

Tue

Reported

4-11 days

Reference Interval

Reports include age appropriate reference interval.

Test Number
 Components
 Reference Interval
  Isobutyrylcarnitine,Urine
Age
 Reference Interval (mmol/mol creatinine)
Less than or equal to 5.5 years Less than or equal to 4.9
Greater than 5.5 years Less than or equal to 2.3

  Butyrylcarnitine, Urine Less than or equal to 0.15 mmol/mol creatinine

Interpretive Data

Methodology: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

If patient is receiving carnitine supplements, results may not be informative.  Clinical correlation is recommended for interpretation of the result.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the U.S. Food and Drug Administration. This test was performed in a CLIA-certified laboratory and is intended for clinical purposes.

Compliance Category

Laboratory Developed Test (LDT)

Note

Hotline History

View Hotline History

 

Hotline History

Date of Change
Test Name Change
Methodology
Performance/Reported Schedule
Specimen Requirements
Reference Interval
Interpretive Data
Note
CPT Code
Component Change
Other Interface Change
New Test
Inactive
03/28/2023
X
N/A

CPT Codes

82017

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Components

Component Test Code* Component Chart Name LOINC
3006179 Creatinine, Urine 2161-8
3006180 Isobutyryl/butyrylcarnitine Urine Interp
3006183 Isobutyrylcarnitine,Urine
3006184 Butyrylcarnitine, Urine 53111-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Acylcarnitines, urine
  • Butyrylcarnitine
  • C4 Acylcarnitine
  • IBD
  • isobutyryl-CoA dehyrogenase deficiency
  • Isobutyrylcarnitine
  • SCAD
  • short chain acyl-CoA dehydrogenase deficiency
Isobutyryl/butyryl-carnitine (C4) Quantitative, Urine